Light bicycle

The utility model relates to a light bicycle, comprising a steering handle bar, a front and a rear wheel, a seat, a tripod, two foot pedals, a control wire and a copper tube, wherein a spring, a hex angle plate, a three tooth angle plate, a hex groove angle and an active pin are arranged in the copper tube. The utility model is characterized in that a plurality of gear sets are positioned on the rear wheel shaft and the copper tube and are meshed with each other, and the tooth number of each gear set is the same; the pin head of the active pin inside the copper tube can be manipulated to insert into the gear groove of different gear set by the control wire to change speed conveniently; the foot pedals and the seat are positioned on the rear wheel shaft, the transmission force of feet stepping on the foot pedal is acted directly on the rear wheel, and the weight center of the rider is also positioned on the rear wheel, thus the utility model has the advantages of light weight and effort saving while in riding.